[Sync EN] Add xlink namespace to URL validation error type XML (#5481)

[github-actions]

Commit: https://github.com/php/doc-en/commit/8352249a84d0b91b38c741ff1c256061127dbfbb
PR: https://github.com/php/doc-en/pull/5481

Fichiers FR à mettre à jour

• reference/uri/uri.whatwg.urlvalidationerrortype.xml